Context Cigarette smoking causes more preventable deaths from cardiovascular disease and cancer than any other modifiable risk factor, but smokers may discount the increased personal risk they face from continued smoking.

Objective To assess smokers'perceptions of their risks of heart disease and cancer.

Design and Setting Telephone and self-administered survey in 1995 of a probability sample of US households with telephones.

Participants A total of 3031 adults aged 25 to 74 years, including 737 current smokers (24.3%). Main Outcome Measures Respondents with no history of myocardial infarction (MI) (96.2%) or cancer (92.9%) assessed their risk of these conditions relative to other people of the same age and sex.

Among current smokers, perceived risks were analyzed by demographic and clinical factors using logistic regression.

Results Only 29% and 40% of current smokers believed they have a higher-thanaverage risk of Ml or cancer, respectively, and only 39% and 49% of heavy smokers (>=40 cigarettes per day) acknowledged these risks.

Even among smokers with hypertension, angina, or a family history of Ml, 48%, 49%, and 39%, respectively, perceived their risk of MI as higher than average.